Add simple precompilation example

[nefrathenrici]

This PR introduces a local packagePrecompileCI that precompiles common methods in ClimaAtmos. For now, it only precompiles spaces for different spatial configurations, but this can be expanded to precompile more methods. This all happens in .buildkite/PrecompileCI/src/PrecompileCI.jl, and the package is then loaded in the driver to load in the precompiled methods.

To use, just import it before ClimaAtmos:
julia --project=.buildkite, then

using PrecompileCI  # Loads the precompiled methods or precompiles if loaded for the first time
import ClimaAtmos as CA
config = CA.AtmosConfig()
sim = CA.get_simulation(config)
CA.solve_atmos!(sim)

I included this as a separate package because precompiling these methods when ClimaAtmos is loaded will add to the TTFX.

To see which methods are actually getting precompiled, see this gist or run:
julia --project=.buildkite/PrecompileCI

using PrecompileTools
PrecompileTools.verbose[] = true
include(".buildkite/PrecompileCI/src/PrecompileCI.jl")

[charleskawczynski]

Suggested change

	println("julia -e 'using Pkg; Pkg.add(\"JuliaFormatter\")'")
	println("julia -e 'using Pkg; Pkg.add(\"JuliaFormatter\")'")
	println()
	println("If you already have it in your local environment, you can use")
	println("julia -e 'using JuliaFormatter; format(\".\")")

[charleskawczynski]

I think it's worth trying this out, maybe we can loop over more configs? But I think it's a good starting point.

[Sbozzolo]

With this PR, users using the driver will need to have PrecompileCI in their environments. This will break people's workflow.

Let's make sure we don't break people's workflow. We could take the opportunity to split the driver into ci_driver.jl (which contains PrecompileCI) and other driver that for the time being could just be running + plotting.

[nefrathenrici]

With this PR, users using the driver will need to have PrecompileCI in their environments. This will break people's workflow.

Let's make sure we don't break people's workflow. We could take the opportunity to split the driver into ci_driver.jl (which contains PrecompileCI) and other driver that for the time being could just be running + plotting.

This only breaks the case of including the driver without using the .buildkite Project. I think splitting out the driver is a larger task which would also break people's workflow and should be separate from this PR. As a temporary workaround I could add a check get(ENV, "CI", false) && import PrecompileCI to ensure that this is only loaded in actual CI runs.